Sewing machine



FIG. 1 is a front elevational view of a sewing machine showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right end elevational view thereof; and

FIG. 5 is a left end elevational view thereof. 

The ornamental design for a sewing machine, as shown. 